Local in mature, often damp, woodland, fens and scrubby heathland throughout England, mainly in southern counties; present at low density throughout north Hampshire, but decidedly scarce in south Hampshire, mainly in the New Forest, and recorded only once on the Isle of Wight. Wingspan 29-32 mm. The main confusion species is Galium Carpet Epirrhoe galiata
— both species have a concave costa — the best distinction is the outer edge of the central cross-band, which is slightly crenulate throughout its length in Large Twin-spot Carpet, but more smoothly sinuate in Galium Carpet. Larva feeds on various herbaceous plants, including Bedstraw, Common Dog-violet, and Primrose.